1. Field of the Invention
The present invention relates to reagents used for and methods for the enumeration of oral gram-negative bacteria, such as Bacteroides melaninogenicus, Capnocytophaga sp. and Eikenella corrodens which are related to periodontal diseases.
2. Description of the Prior Art
Bacteroides melaninogenicus and Capnocytophaga sp. in subgingival plaque are bacteria often studied in relation to periodontal diseases, particularly the former in relation to advanced periodontitis, and the latter to periodontosis and children's periodontal diseases. For the detection and the enumeration of these oral bacterial, an authorized method for cultivation has usually been adopted. In this method, a sample taken from a patient is incubated on a blood agar plate for about 7 days, and is then enumerated by counting special colonies--the colonies of Bacteroides melaninogenicus are black and those of Capnocytaphaga sp. are wet spreading--on the plate. Eikenella corrodens, which is also studied in relation to advanced periodontitis, is enumerated by counting colonies on a selective medium, because special colonies are not formed by the usual cultural method.
However, the method of the detection and the enumeration of the above-mentioned oral bacteria by cultivation are very complicated in operation and are very expensive. Moreover, they require a long period of time--about a week or more--for cultivation and much loss of time for the enumeration. It is, therefore, difficult to quickly and easily enumerate the oral gram-negative bacteria by adopting the usual cultural method.